This invention concerns a ruler device for measuring relatively short distances, and for teaching the user the principles of distance measurement and the concept of fractions of a unit of measurement.
Young children and persons having various learning impediments or physical handicaps find difficulty in using an ordinary ruler for measurement of the straight linear distance between two points. For example, even when the distance to be measured is across a flat surface, a visually impaired or blind person will have difficulty in using an ordinary ruler. Although braille-imprinted rulers have been designed to aid blind persons, the braille markings are effective in designating only relatively large intervals such as one inch spaces, and are not generally effective in designating fractions of an inch as small as 1/8 inch.
The concept of fractions of an inch is frequently not easily grasped by persons of slow learning ability taught by abstract or mathematical approaches without visualization means, and such persons generally do not comprehend the standard scale markings on a conventional ruler.
U.S. Pat. No. 2,803,069 to Struna discloses an educational device for the use in front of a classroom of students for teaching the concept of fractions of units of linear measurement. However, its requisite oversize nature may be confusing to students who cannot correlate the deliberately exaggerated size of the teaching device with the actual dimensions of distances they will be trying to measure. Furthermore, the Struna device is of complex construction and not intended for actual use by students in attempting real measurements. Even if the Struna device were scaled down to coincide with dimensions of a standard ruler, its complexity and attendant high cost would preclude widespread use as a teaching aid for individual students. It is to be further appreciated that students in the lower school grades would generally be reluctant to add a bulky ruler device to their already cumbersome daily carrying load of books and other school supplies.
It is accordingly an object of this invention to provide a ruler device for measuring distance and for providing instruction in the use of a ruler.
It is another object of this invention to provide a ruler as in the foregoing object which provides functionally symbolic means for perceiving fractions of an inch.
It is a further object of the present invention to provide a ruler of the aforesaid nature which enables a blind person to measure distance to within small fractions of an inch.
It is still another object of this invention to provide a ruler of the aforesaid nature of sufficiently compact construction and low cost that it may find widespread use amongst students having a need for such ruler.
These objects and other objects and advantages of the invention will be apparent from the following description.